Heat the butter and oil together before adding the leeks and cooking until softened. Add the garlic and mushrooms and cook until tender. Season with salt and freshly ground black pepper before adding the breadcrumbed and combining. Have your butcher debone a chicken for you or simply keeping the chicken whole if this isn’t an option. Lay the chicken skin side down over the pancetta and fill the center with the stuffing. Carefully roll to secure the filing. Ensuring the pancetta is covering the chicken. Using butchers twine: Secure the chicken before either placing in the oven to roast at 180”C for 45 minutes or place in the LG infrared convection oven and roast for 30 minutes. After roasting allow the roast to rest for 5 minutes before slicing and serving